a webley 1-piece mount. If so, it is a good mount and you should have no problems with it. The only thing that might be required is a little BLUE loctite on the screws if they keep loosening up. If you plan on shooting 5 to 50 yards, you may consider sighting your rifle in at 30 to 33 yards. Depending on the specific velocity of your rifle and its pellet of choice, 30-33 yards will likely be your optimum zero point.
As far as pellets go, try as many as you can and then use only the one that groups the tightest at the distances you want to shoot. 5-50 yards is a pretty broad range for a 52 in .22, so you are probably looking at a JSB Exact, Crossman Premier, Beeman FTS, or RWS Superdome. My first guess would be the Exact followed by the Premier, but it is entirely up to your gun. If none of the above group to your liking, don't be afraid to try others. Don't forget to keep checking all of the screws on your scope, mounts, and rifle, if you are having difficulty getting good groups. A little carefully applied BLUE loctite may be required. Good luck.